I knew nothing about Alexithymia before today. I didn't even know it existed, so take my little theory for what you will.

I feel like for some people with Alexithymia, part of what lies at the heart of it is a suppression of honesty. Difficulty with being honest with oneself and honestly expressing what one truly feels. When one doesn't have the room to express themselves and how they feel openly around others, perhaps it makes it more difficult for them to do so internally. Thus, they struggle to identify what it is they're feeling because they haven't practiced being honest about what it is they feel enough.

Anyway, I thought I'd just think out loud in a comment. Thanks for the informative article!